1. Field of the Invention
The invention relates to a process for recycling commingled plastics. More particularly, the invention relates to a process for shredding, separating and blending commingled poly(acrylonitrile-c-butadiene-c-styrene) (ABS) and polycarbonate ABS (PCABS) to produce recycled ABS/PCABS useful in the manufacture of products.
2. Description of the Prior Art
ABS is extensively used in the manufacture of inexpensive, durable products. The durability of ABS has made it a primary material in the manufacture of products such as, computer housings, televisions and computer monitor housings, automobile components, etc.
Unfortunately, however, ABS is somewhat expensive when supplied in its purest form. As such, the cost of manufacturing some products with ABS is prohibitively expensive despite the fact that the material characteristics of the ABS are well suited for the manufacture of the products.
Plastic recycling has received substantial interest in recent years and many advances have been made in both recycling techniques and the devices manufactured from recycled plastics. Unfortunately, many of these processes are somewhat time consuming and are not appropriate for recycling certain goods. Existing recycling techniques require that the plastics be identified, i.e., "fingerprinted", and separated based upon their specific composition (for example, by coding as commonly found on many products sold today) before they may be fully recycled for subsequent use. Where the commingled plastics are not separated prior to subsequent recycling steps, the resulting recycled product is a useless collection of commingled recycled plastic.
Where the recycled goods are composed of a single plastic component (for example, plastic soda and milk containers), recycling is highly cost effective and leads to many useful products. However, the necessity of separating the assortment of plastic components prior to shredding and granulating makes recycling commingled plastic products highly time consuming and prohibitively expensive. Existing recycling techniques are, therefore, not appropriate where the recycled goods include many components composed of various plastics.
For example, where it is desired to recycle the plastic components of a computer housing (which is primarily composed of ABS, PCABS, and other plastics) to take advantage of the recycled ABS, the computer housing must first be separated into various components representing the many plastics used in the construction of the computer housing. This is highly time consuming, and makes recycling computer housings cost prohibitive. Such limitations are commonly found with ABS products one might consider appropriate for recycling.
The lack of an effective recycling process for those products already manufactured from ABS leaves previously used ABS products wasted once the useful life of the manufactured product is reached. Many materials have found a second life through recycling. However, a process for refining the used material must be developed before the material may find a second life in another product. Often, the second life of a product requires that the material be used in an environment where the aesthetic appearance of the material is not as important as when the material was used for its original purpose.
For example, it has been found that ABS is ideal for use as a substrate in the manufacture of decorative laminates. A substrate for a decorative laminate is generally not seen by the public and there is no requirement that the decorative laminate substrate be aesthetically pleasing. As such, although the cost of pure unprocessed ABS is prohibitively expensive when used in the manufacture of substrates, less expensive, recycled ABS is an ideal candidate for use in the manufacture of decorative laminate substrates.
Unfortunately, no process is currently known for effectively and efficiently recycling ABS for subsequent use. The present invention provides a process for recycling ABS in a manner permitting previously used ABS to obtain a second life. The present process employs shredding, separating and blending to recycle used ABS for subsequent use in other products, for example, substrates of decorative laminates.